2 places I recommend
These are the two restaurants in Abu Dhabi I have eaten at myself and would recommend.
A Cantonese restaurant at the Rosewood, also on Al Maryah Island. Nice and casual, with solid quality food.
Address: Rosewood Abu Dhabi, Al Maryah Island, Abu Dhabi, United Arab Emirates
A steakhouse at the Four Seasons on Al Maryah Island. The food was really delicious and I loved the design of the place. It's temporarily closed but hopefully they'll be back soon.
Address: Four Seasons Hotel, Al Maryah Island, Abu Dhabi, United Arab Emirates